The biggest difference between encrypted data and hashed data is that encrypted data can be decrypted later. Hash algorithms such as MD5 are one way hashing algorithms which means that the value that is returned can’t be decrypted back to the original value.
It is important to know the difference between the two when designing your database encryption schema. If you don’t need to retrieve the encrypted value then only store the hash. This way you don’t have the actual data for anyone to steal.
Denny